ASP Charset Convert Tutorial

Chilkat ActiveX Downloads

ActiveX for 32-bit and 64-bit Windows

Convert Unicode to utf-8, then convert utf-8 to iso-8859-1.

<% @CodePage = 65001 %>
<% Response.CodePage = 28591 %> 

<%
' Convert utf-8 (code page 6500) to iso-8859-1 (code page 28591)
'
' IMPORTANT: Remember to save this .asp files in the utf-8 character encoding.
' IMPORTANT: Remember to save this .asp files in the utf-8 character encoding.
' IMPORTANT: Remember to save this .asp files in the utf-8 character encoding.

' The first directive, "@CodePage" is the code page of the ASP file.
' When you save the .asp file using your editor, save it in this code page.
' This is the charset used for literal strings within your ASP scripting.
' 
' The Response.CodePage directive indicates the charset encoding emitted
' by Response.Write.  

' The charset specified in the <meta> tag, as shown below, must match
' the Response.CodePage.  
%>

<html>
<head><meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1"></head>
<body>
<%

myStr = "eèéêë"
' myStr is a String.  Strings in ASP are Unicode (2 bytes/char).
' This particular .asp file is saved in the utf-8 encoding (our @CodePage is utf-8).
' Therefore, the ASP scripting engine converts the literal string from utf-8 to
' Unicode.  (utf-8 is actually the multibyte encoding of Unicode, but it is a different
' character encoding than the 2-byte/char Unicode)

' Create a Chilkat Charset object to convert and examine the character data.
set cc = Server.CreateObject("Chilkat_9_5_0.Charset2")
cc.UnlockComponent "Anything for 30-day trial"

' Turn on "SaveLast" so we can see what happened...
cc.SaveLast = 1

cc.ToCharset = "utf-8"
' If your source data is a String (i.e. not a byte array / Variant) it is Unicode.
' The string type in ASP is *always* Unicode (i.e. ucs-2).
utf8Bytes = cc.ConvertFromUnicode(myStr)

' Examine the bytes passed to the converter and the bytes returned:
inHexStr = cc.LastInputAsHex
outHexStr = cc.LastOutputAsHex

Response.Write "<b>Unicode to utf-8 conversion:</b><br>"
Response.Write "Input: " + inHexStr + "<br>"
Response.Write "Output: " + outHexStr + "<p>"

' This is the output:
' Input: 6500 E800 E900 EA00 EB00
' Output: 65C3 A8C3 A9C3 AAC3 AB

' We can clearly see that the input was Unicode (2 bytes/char).
' The output is utf-8.  The individual characters are: 65 C3A8 C3A9 C3AA C3AB

' Now that we have utf-8, convert it to iso-8859-1:
cc.FromCharset = "utf-8"
cc.ToCharset = "iso-8859-1"
isoBytes = cc.ConvertData(utf8Bytes)

' Look at the results:
inHexStr = cc.LastInputAsHex
outHexStr = cc.LastOutputAsHex
Response.Write "<b>utf-8 to iso-8859-1 conversion:</b><br>"
Response.Write "Input: " + inHexStr + "<br>"
Response.Write "Output: " + outHexStr + "<p>"

' This is the output:
' Input: 65C3 A8C3 A9C3 AAC3 AB
' Output: 65E8 E9EA EB

' The iso-8859-1 charset encoding is 1-byte/character, and we can see that it
' is correct in the output.

' This ASP page's Response Code page is iso-8859-1, so we can emit the bytes
' directly with Response.BinaryWrite...
Response.Write "This is emitted with Response.BinaryWrite: "
Response.BinaryWrite isoBytes
Response.Write "<p>"

%>
</body>
</html>